1. Field of the Invention
The present invention relates to a method of synchronizing the injection with the engine phase in an engine with electronic injector control.
2. Description of the Related Art
With the development of new generations of engines, particularly direct injection engines, electronic control of fuel injection into the cylinders has become widespread. It permits total control of the instant at which the fuel is injected into the cylinder. Thus, it enables the fuel to be injected with an accuracy of 3°, in other words within a very precise injection interval.
In a four-stroke engine, it is important to know not only the position of the pistons in the cylinders, and consequently the position of the crankshaft, but also the phase of the engine. Thus, when the piston in a cylinder is at top dead center, it is important to know whether it is at the end of the compression stroke or at the end of the exhaust stroke. Two position sensors are used for this purpose. A first sensor on the crankshaft indicates the relative position of the pistons in the cylinders and a second sensor on the camshaft indicates the engine phase (induction, compression, expansion or exhaust).
Generally, the information supplied by the sensor located on the camshaft is used only when the engine is started, to determine the cylinders into which the first injections are to be made. The injection sequence is then implemented according to a predetermined cycle and only synchronization with the crankshaft is required.